Controlled growth mechanism of poly (3-hexylthiophene) nanowires

Abstract

Synthesis of 1D-polymer nanowires by a self-assembly method using marginal solvents is an attractive technique. While the formation mechanism is poorly understood, this method is essential in order to control the growth of nanowires. Here we visualized the time-dependent assembly of poly (3-hexyl-thiophene-2,5-diyl) (P3HT) nanowires by atomic force microscopy and scanning tunneling microscopy. The assembly of P3HT nanowires was carried out at room temperature by mixing cyclohexanone (CHN), as a poor solvent, with polymer solution in 1,2-dichlorobenzene (DCB). Both π-π stacking and planarization, obtained at the mix volume ratio of P3HT (in DCB):CHN (10:7), were considered during the investigation. We find that the length of nanowires was determined by the ordering of polymers in the polymer repetition direction. Additionally, our density functional theory calculations revealed that the presence of DCB and CHN molecules that stabilize the structural distortions due to tail group of polymers was essential for the core-wire formation.

Aggregation Behavior of Poly(3‐hexylthiophene) in Solvent Mixtures: Linear Solvation Energy Relationship (LSER) Modeling and COSMO‐RS Calculations

“…Also, mixtures of good and poor solvents have the capacity to generate a larger yield of aggregates than pure marginal solvents, which may impose limitations on the latter toward certain applications, such as optimizing the doping efficiency of P3HT . Despite these advantages of solvent mixtures, the available literature on the assembly and crystallization of P3HT in solvent mixtures is rather scarce, compared to those involving pure solvents . Furthermore, most of these endeavors exploit the fabrication of P3HT aggregates as a means to (1) manipulate the morphology of films and P3HT/nanoparticle composites, (2) affect charge transport and field effect mobility, or (3) study the structure and photophysics of the aggregates.…”

Poly(3‐hexylthiophene) aggregation at solvent–solvent interfaces

“…Kiymaz et al reported a similar trend from high aspect ratio fibers to in P3HT films prepared at multiple time intervals after adding the poor solvent, cyclohexanone, to a P3HT:chlorobenzene solution (see Figure in ref. ).…”

“…In this context, the mixing kinetics can modulate the assembly process in such a way that small amounts of fibrous aggregates are fabricated in the 70:30 CF:HEX FAC samples. This supposition is consistent with the fact that the fibrous features in the film are observed when we used the smaller diameter vial and supports the claim by Kiymaz et al, that the thickness of P3HT nanowires is dictated by the “nanowire creation velocity.”…”

“…In all of our previous investigations we used the same method to generate the P3HT aggregates, wherein the poor solvent was rapidly injected into a solution of well‐dissolved, amorphous P3HT. In a recent study Kiymaz et al used an interfacial approach to generate nanofibers of P3HT by adding a poor solvent, cyclohexanone, on top of a P3HT:dichlorobenzene solution . Using atomic force microscopy (AFM) the authors studied the morphological changes of P3HT films spin‐coated at different time intervals.…”

The Electronic, Optical, and Thermoelectric Properties of Monolayer PbTe and the Tunability of the Electronic Structure by External Fields and Defects

“…Such understanding would also help in creating ideas to control defects and in this way to prepare 2DMs with novel properties. Point defects, including vacancy, impurity, adsorption, and substitution of atoms and different methods such as strain engineering and applying an electric field can tailor the electronic properties of 2DMs, can be used for a wide range of applications.…”